1. Technical Field
The present invention relates to a heat-dissipating apparatus which can position a light emitting diode (LED) more precisely.
2. Related Art
A vehicle is equipped with vehicle lamps. Vehicle lamps have lighting function and signaling function, among others. That is, vehicle lamps enable the driver of the vehicle to easily detect objects around and ahead of the vehicle while driving at night or in a dark area. They also inform other vehicles and road users of the vehicle's driving state. For example, a headlamp and a fog lamp are designed for the lighting function, and a direction indicator, a taillight, a brake light, and a side marker are designed for the signaling function. Typically, halogen lamps and high intensity discharge (HID) lamps are used as a light source.
Recently, LEDs were adopted as a light source for vehicle headlamps or lighting devices. The color temperature of LEDs is approximately 5500 kelvin (K) which is close to sunlight. Thus, LEDs cause less eyestrain than other light sources. Since LEDs are small-sized, lamps using LEDs can be designed with a greater degree of freedom. In addition, LEDs are economical since they are semi-permanent. In this regard, LEDs are being introduced to reduce complexity in the configuration of lamps and prevent an increase in the number of processes required to manufacture the lamps. That is, attempts are being made to extend the life of lamps and reduce the space occupied by lamp apparatuses by taking advantage of properties of LEDs.
However, temperature remains a major challenge in the adoption of LEDs as a light source for vehicle lamps. As the performance of LEDs improves, the LEDs emit heat at higher temperatures, and the heat at higher temperatures reduces the performance of the LEDs. That is, as the temperature of LEDs increases, the luminous efficiency thereof significantly deteriorates. To address this problem, the junction temperature of LEDs must be increased, or a heat-dissipating apparatus for lowering the ambient temperature must be installed. In particular, since there is a limit to increasing the junction temperature, the heat-dissipating apparatus must be used efficiently. Although the junction temperature of LEDs is expected to increase continuously, an improved heat-dissipating apparatus is essential to increase the efficiency of a lamp more effectively.
FIG. 1 is a longitudinal cross-section of a conventional LED heat-dissipating apparatus 10. Referring to FIG. 1, a thermally conductive material 13 is disposed under the LED-mounting block 12 having an LED 11 mounted thereon. The LED-mounting block 12 and the thermally conductive material 13 are coupled together to a heat sink 14 by fixing bolts 15. The conventional LED heat-dissipating apparatus 10 has the following problems. When the LED-mounting block 12 is coupled to the heat sink 14 by the fixing bolts 15, the thermally conductive material 13 is compressed by the elasticity thereof, which may cause the LED 11 to be moved out of its intended position. In addition, after the thermally conductive material 13 is coupled to the heat sink 14, aiming control is required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.